Commutator-cylinder.



H; M. WOOD.

coMmumoa CYLINDER. APPLICATION FILED HULZG' 9|?- .1,289,344. Patented Dec. 31,1918.

INVENTOR Harry/*7, M aad' w y M l/ ATTORN EY WITNESSES:

UNITED STATES PATENT carie HARRY M. WOOD, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR '10 \VES'TINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

COMMUTATOR-CYLINDER.

Application filed. January 26, 1917.

To all whom it may concern:

Be it known that I, HARRY M. -Wooo, a citizen of the United States, and a resident of Edgework Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Commutator-Cylinders, of which the following is a specification.

My invention relates to the construction of commutator cylinders for dynamo-electric machines, and it has for its object to provide a commutator cylinder that is particularly adapted for use in connection with dynamo-electric machines of the high-volt age type.

In the construction of connnutator cylinders for high voltage, it is essential that sufficient insulation be provided in order to prevent electrical discharges bctweei'i the conducting segments which are at machine potential and the clamping rings of which are at ground potential. The obvious expedient is to increase the length of the creepage path which is usually defined as the shortest distance over the exposed surfaces of the insulating material between the live parts and the ground. The desired results have heretofore been obtained by merely extending the insulation longitudinally beyond the ends of the conducting segments, but, owing to the space limitations existing in certain types of apparatus, such as railway motors, this has not always been found practicable.

According to the present invention, I provide a high-voltage commutator cylinder having a safe creepage path wherein the overall length of the commutator cylinder is actually decreased, as compared with existing types. This result is obtained by the use of a novel form of clamping ring for the commutator segments that is provided with a projecting portion which extends above the engaging circumferential surfaces of the clamping ring and of the segments for a greater distance than it extends beyond the ends of the segments. The layer of insulating material that is usually provided between the clamping ring and the segments is extended beyond the ends of the segments and is supported by the projectlng portion of the clamping ring.

In the accompanying drawings, Figure 1 is a transverse sectional view of a commutator cylinder embodying my invention, and

Specification of Letters Patent.

Patented Dec. 31, 1918.

Serial No. 144,667.

Figs. 2, 3 and 1 are fragmentary views similar to Fig. 1 showing modifications of my invention.

A plurality of conducting and insulating segments 1 and 2, respectively, are circumferentially arranged upon supporting spider 3 and a clamping ring 4 that is provided with a V-shaped annular end face which engages a corresponding V-shaped groove provided in the segments 1 and2 adapted to maintain the segments in posi tion upon the spider 3 by means of bolts 5. The clamping ring 4 is further provided with a projecting portion 6 that extends laterally above the engaging circumferential surfaces 1 and i of the segments and of the clamping ring. A layer 7 of insulating material is interposed between the commutator segments and the clamping ring at and is extended beyond the ends of the segments to cover the adjacent surface of the projecting portion 6 of the clamping ring a.

A modification of my invention is shown in Fig. 2 wherein the projecting portion 6 of of the clamping ring at is provided with an annular recess 8 within which is located a reinforcing ring 9 that is preferably com posed of a hard and durable insulatin ma terial possessing considerable mechanical strength. In this modification, the project ing portion 6 need not be laterally extended as far as shown in Fig. 1, because of the support given to the insulating layer 7 by the reinforcing member 9.

A further modification of my invention is shown in Fig. 3 wherein the layer 7 of insulating material extends only to the base of the portion 6 and terminates in an external flange 10. A second layer 11 of insulating material covers the face of the projecting portion 6 and is provided with an internal flange 12 that fits within the flange 10 of the layer 7. The clamping ring 4 is provided with an annular groove 13 that is filled with a molded insulating material 14 in order to provide an effective seal against creepage through the joint between the layers of insulating material.

A still further modification of my invention is shown in Fig. 4 wherein the projecting portion 6 of the clamping ring is provided with a corrugated or wave-like surface 15 that is covered with an extended portion of the insulating layer 7.

While I have shown my invention in several preferred forms, it is apparent that other constructions may be employed I for providing an insulating surface extending laterally above the engaging circumferential surfaces .of the commutator segments and clamping ring Without departing from the spirit of my invention and I desire, therefore, that only such limitations shall be imposed thereon as come within the scope of the appended claims.

I claim as my invention:

1. A commutator cylinder comprising circumferentially arranged conducting and'insulating segments, and a clamping ring therefor having an insulated portion projecting beyond the ends and above the outer surface of said segments.

2. A commutator cylinder comprising circumferentially arranged conducting and insulating segments, and a clamping ring therefor having a portion projecting beyond the ends and above the outer surface of said segments and a layer of insulating material covering said projecting portion.

3. A commutator cylinder comprising circumferentially arranged conducting and insulating segments, and a clan'lping ring therefor having a portion projecting laterally above the surface of said segments and a layer of insulating material covering said projecting portion.

4. A commutator cylinder comprising circumferentially arranged conducting and insulating segments, and a clamping ring therefor having a surface in spaced relation With an inner circumferential surface of said segements, the said ring being provided With a portion projecting beyond the ends of said segments and above the said surfaces,

and a layer of insulating material covering said projecting portion.

5. A commutator cylinder comprising circumferentiall arranged conducting and insulating segments, a clamping ring therefor having a surface in spaced relation With an inner circumferential surface of said segments, the said ring being provided with a portion that projects above the said surfaces for a greater distance than it projects beyond the ends of said segments, and a layer of insulating material covering said projecting portion.

6. A commutator cylinder comprising cii cumferentially arranged conducting and insulatin segments, a clamping ring therefor having a surface in spaced relation With an inner circumferential surface of said seg ments and a layer of insulating material interposed between said ring and said segments, the said insulating material being eX- tended beyond and above the said surfaces of said segments and of said ring.

7. A commutator cylinder comprising circumferentially arranged conducting and insulating segments, a clamping ring therefor having a surface in spaced relation With an inner circumferential surface of said segments, and a layer of insulating material interposed between said ring and said seg-' ments, the said insulating material projecting above the said surfaces for a greater distance than it projects beyond the ends of said segments.

In testimony whereof, I have hereunto subscribed my name this nineteenth day of January, 1917.

HARRY M. 001).

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

